Create table
Clients (
	Client	varchar(25)  ,
 	Name	varchar(100),
 	Identifier	varchar(25),
 	Adress	varchar(50),
 	Contact	varchar(50),
 	Tel	varchar(25),
 	Remark	varchar(100),
       CONSTRAINT PK_Clients PRIMARY KEY (Client)     
)

Create table
Companies (	
	Company	varchar(25)  ,
 	Name	varchar(100),
 	Prefix	varchar(3),
 	Identifier	varchar(25),
 	Account	varchar(25),
 	Adress	varchar(50),
 	Contact	varchar(50),
 	Tel	varchar(25),
       CONSTRAINT PK_Companies PRIMARY KEY (Company)     
                              )



Create table
Contracts  
  (	Id	numeric(4,0)  IDENTITY(1,1),
       [Contract]  varchar(50) not null,  
 	Number	varchar(10) not null,
 	Dt	date,
 	Client	varchar(25),
 	Company	varchar(25),
	CONSTRAINT PK_Contracts PRIMARY KEY (Id)     
                                )


ALTER TABLE Contracts  WITH CHECK ADD  CONSTRAINT FK_Contracts_Clients
FOREIGN  KEY (Client)
REFERENCES  Clients(Client)
ON UPDATE CASCADE
ON DELETE CASCADE



ALTER TABLE Contracts  WITH CHECK ADD  CONSTRAINT FK_Contracts_Companies 
FOREIGN  KEY (Company)
REFERENCES  Companies(Company)
ON UPDATE CASCADE
ON DELETE CASCADE